Not applicable.
The present invention relates to adjustment mechanisms and, more particularly, to mechanisms for adjustment and locking of the workpiece support surface of devices, such as, for example, woodworking and metal working devices. The present invention may be adapted for use with any device having one or more support surfaces that may be adjusted in orientation relative to one or more other elements of the device. Examples of possible applications of the adjustment mechanism of the present invention include use of the invention as a mean for adjusting and locking the orientation of the rotatable workpiece support surface of a power operated miter saw.
A number of known cutting devices include a driven cutting member such as, for example, a circular saw blade, and a generally planar workpiece support surface. In such devices, the workpiece support surface often includes two or more portions, and wherein the cutting member is rotatably mounted on one of the portions and the portions are adapted for adjustment relative to each other. For example, the workpiece support surface of cutting a device may include a base portion and a table portion, wherein the cutting blade is coupled to the table portion and the table portion is adapted for movement relative to the base portion. In such a device the base portion generally includes some type of workpiece guide, such as a fence, fixed thereto. The workpiece guide is generally adapted to support a workpiece in place relative to the base portion while the cutting member acts to cut the workpiece. Movement of the table portion relative to the base portion thus results in movement of the cutting member relative to the workpiece guide. Accordingly, in such devices, the cutting member may be oriented in various positions relative to a workpiece supported against the workpiece guide.
A specific example of a cutting device having the foregoing arrangement of elements is a power operated miter saw. Miter saws commonly include a table portion that is rotatable relative to the base portion to thereby allow the saw blade to change orientation relative to the workpiece guide of the miter saw. Adjustment of the orientation of the table portion relative to the base portion allows the saw blade to execute cuts at various miter angles through a workpiece supported by the workpiece guide.
In the example of a miter saw, it is important that the operator be able to easily and accurately position the cutting member relative to a workpiece supported against the workpiece guide and releasably lock the cutting member in the desired position. In particular, it is desirable that the position of the table portion and the attached cutting member be precisely adjustable to desired miter angles relative to the base portion and its attached workpiece guide. An adjustment mechanism is typically provided for adjusting the angle of the table portion relative to the base portion and for releasably locking the table portion in place relative to the base portion. In that regard, a variety of adjustment mechanisms are known to provide adjustment and releasable locking. However, most of these adjustment mechanisms are deficient in some respect. For example, certain of the known adjustment mechanisms that incorporate a detent or indexing mechanism to fix the position of the table portion relative to the base portion generally provide only for coarse adjustment of the table portion relative to the base portion. Other known adjustment mechanisms rely on frictional contact to fix the table portion relative to the base portion. Such mechanisms generally require significant effort on the part of the operator to generate a frictional force that is sufficient to suitably fix the table portion relative to the base portion.
Accordingly, it will be appreciated that there is a need to improve the design of adjustment mechanisms for accurately positioning and releasably locking the table portion of a miter saw or other similarly constructed cutting or abrading device relative to the base portion of the device. In particular, it would be advantageous to provide an adjustment mechanism by which the orientation of the rotatable table portion of a miter saw or the like may be quickly and easily repositioned and locked relative to other elements of the device such a mechanism would allow for rapid and precise adjustment and locking of the angle of the cutting member relative to the device""s workpiece guide. More broadly, it would be advantageous to provide an improved adjustment mechanism for adjusting and locking a position of a first surface of a woodworking, metal working, or other device relative to other elements of the device.
The present invention is drawn to an apparatus which may be used to releasably adjust the position of a first portion of a device relative to a second portion of the device. The first portion includes a first surface, and the second portion includes a second surface. A workpiece support surface is defined by the first and second surfaces, and the first surface is rotatable relative to the second surface. A locking mechanism is provided to selectively restrain rotation of the first surface relative to the second surface. An indexing mechanism also may be provided including a detent mechanism which selectively restrains rotation of the first surface relative to the second surface in one of a plurality of predetermined positions.
The present invention also is directed to an adjustment mechanism for pivotably adjusting a position of a first surface of a first portion of an apparatus relative to a second surface defined by a second portion of the apparatus. The first portion is rotatable relative to the second portion. The adjustment mechanism includes a locking mechanism selectively restraining rotation of the first portion relative to the second portion. The locking mechanism includes a locking frame that is pivotably mounted on the first portion and includes a locking surface that selectively frictionally engages an engagement surface on the second portion. The adjustment mechanism also includes an actuating mechanism that selectively pivots the locking surface into frictional engagement with the engagement surface.
The present invention is additionally directed to an adjustment mechanism for adjusting the position of a first surface of a first portion relative to a second surface of a second portion, and wherein the second portion also includes an indexing surface including at least one indexing slot. The first portion is rotatable relative to the second portion. The adjustment mechanism includes an indexing mechanism which, in turn, includes a detent mechanism selectively restraining movement of the first surface relative to the second surface in one of a number of predetermined positions. The detent mechanism includes a detent body pivotably mounted on the first portion and having a detent pin that may selectively engage at least one indexing slot. The detent mechanism further includes a detent actuating mechanism contacting the detent body and selectively moving the detent pin out of the indexing slot.
The present invention additionally also is directed to an adjustment mechanism for pivotably adjusting the workpiece support surface of a woodworking machine. The workpiece support surface includes a first surface and a second surface, the first surface being defined by a table portion that is rotatable relative to a base portion defining the second surface. The adjustment mechanism includes a locking mechanism having a locking bar comprising a locking surface. The locking mechanism selectively restrains rotation of the table portion relative to the base portion. The indexing mechanism includes a detent mechanism, and the indexing mechanism selectively restrains rotation of the table portion relative to the base portion in one of a number of predetermined positions.
The present invention addresses shortcomings of the known adjustment mechanisms by providing a quick and easily manipulable arrangement for adjusting the position of a surface such as, for example, a workpiece support surface of a woodworking or other machine or device, relative to another surface or element. These and other details, features and advantages will be apparent to those of ordinary skill as the following detailed description of embodiments of the invention proceeds.